| Message ID | 1412095115-28982-1-git-send-email-marcel.a@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Tue, Sep 30, 2014 at 07:38:35PM +0300, Marcel Apfelbaum wrote: > Scanning a lot of devices during boot requires a lot of time. > On other scenarios there is a need to bind a driver to a specific slot. > > Binding devices to pci-stub driver does not work, > as it will not differentiate between devices of the > same type. Using some start scripts is error prone. > > The solution leverages driver_override functionality introduced by > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > Author: Alex Williamson <alex.williamson@redhat.com> > Date: Tue May 20 08:53:21 2014 -0600 > > PCI: Introduce new device binding path using pci_dev.driver_override > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > driver[0001:02:03.4]=pci-stub > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > --- > Notes: > - For the moment only 32 slots can be assigned specific driver. > - I have further ideas on top of this patch based on your reviews. > I thought of: > - Use wildcards to specify entire buses/devices, something like: > driver[0001:02:*.*]=pci-stub > - Use comma to separate several devices: > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > - Make domain optional: > driver[00:03.0]=pci-stub > > Comments will be appreciated, > Thanks, > Marcel > > Documentation/kernel-parameters.txt | 4 +++ > drivers/pci/bus.c | 1 + > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > drivers/pci/pci.h | 1 + > 4 files changed, 67 insertions(+) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 5ae8608..c1cbb4c 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > pcie_scan_all Scan all possible PCIe devices. Otherwise we > only look for one device below a PCIe downstream > port. > + driver Provide an override to the devid<->driver mapping > + for a specific slot. > + Bind PCI slot 0001:02:03.4 to pci-stub by: > + driver[0001:02:03.4]=pci-stub > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > Management. > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > index 73aef51..7a7ed85 100644 > --- a/drivers/pci/bus.c > +++ b/drivers/pci/bus.c > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > * are not assigned yet for some devices. > */ > pci_fixup_device(pci_fixup_final, dev); > + pci_device_setup_driver_override(dev); > pci_create_sysfs_dev_files(dev); > pci_proc_attach_device(dev); > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index b7678be..0a3e07c 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > } > EXPORT_SYMBOL(pci_fixup_cardbus); > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > + > +struct driver_override_entry { > + unsigned int domain; > + unsigned char bus; > + unsigned int devfn; > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > +}; > + > +static struct driver_override_entry __initdata > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > +static int driver_override_num_entries __initdata; > + > +void pci_device_setup_driver_override(struct pci_dev *dev) > +{ > + int i; > + > + for (i = 0; i < driver_override_num_entries; i++) { > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > + dev->bus->number != driver_override_map[i].bus || > + dev->devfn != driver_override_map[i].devfn) > + continue; > + > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > + DRIVER_OVERRIDE_NAME_LENGTH, > + GFP_KERNEL); You allocate this entry but never free it? Shouldn't allocation failure be handled in some way? > + break; > + } > +} > + > +static void __init pci_parse_driver_override(char *str) > +{ > + unsigned int domain, bus, dev, fn; > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > + int ret, next_entry; > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > + > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > + > + if (ret != 5) { > + pr_err("PCI: Invalid command line: driver%s\n", str); > + return; > + } > + > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > + return; > + } > + > + next_entry = driver_override_num_entries++; > + driver_override_map[next_entry].domain = domain; > + driver_override_map[next_entry].bus = bus && 0xff; > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > + memcpy(driver_override_map[next_entry].driver_name, > + driver_name, sizeof(driver_name)); > +} > + > static int __init pci_setup(char *str) > { > while (str) { > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > pcie_bus_config = PCIE_BUS_PEER2PEER; > } else if (!strncmp(str, "pcie_scan_all", 13)) { > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > + } else if (!strncmp(str, "driver", 6)) { > + pci_parse_driver_override(str + 6); > } else { > printk(KERN_ERR "PCI: Unknown option `%s'\n", > str); > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 0601890..023d78b 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -197,6 +197,7 @@ enum pci_bar_type { > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > int crs_timeout); > int pci_setup_device(struct pci_dev *dev); > +void pci_device_setup_driver_override(struct pci_dev *dev); > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > struct resource *res, unsigned int reg); > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > -- > 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2014-10-01 at 09:52 +0300, Michael S. Tsirkin wrote: > On Tue, Sep 30, 2014 at 07:38:35PM +0300, Marcel Apfelbaum wrote: > > Scanning a lot of devices during boot requires a lot of time. > > On other scenarios there is a need to bind a driver to a specific slot. > > > > Binding devices to pci-stub driver does not work, > > as it will not differentiate between devices of the > > same type. Using some start scripts is error prone. > > > > The solution leverages driver_override functionality introduced by > > > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > > Author: Alex Williamson <alex.williamson@redhat.com> > > Date: Tue May 20 08:53:21 2014 -0600 > > > > PCI: Introduce new device binding path using pci_dev.driver_override > > > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > > driver[0001:02:03.4]=pci-stub > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > > --- > > Notes: > > - For the moment only 32 slots can be assigned specific driver. > > - I have further ideas on top of this patch based on your reviews. > > I thought of: > > - Use wildcards to specify entire buses/devices, something like: > > driver[0001:02:*.*]=pci-stub > > - Use comma to separate several devices: > > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > > - Make domain optional: > > driver[00:03.0]=pci-stub > > > > Comments will be appreciated, > > Thanks, > > Marcel > > > > Documentation/kernel-parameters.txt | 4 +++ > > drivers/pci/bus.c | 1 + > > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > > drivers/pci/pci.h | 1 + > > 4 files changed, 67 insertions(+) > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > index 5ae8608..c1cbb4c 100644 > > --- a/Documentation/kernel-parameters.txt > > +++ b/Documentation/kernel-parameters.txt > > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > pcie_scan_all Scan all possible PCIe devices. Otherwise we > > only look for one device below a PCIe downstream > > port. > > + driver Provide an override to the devid<->driver mapping > > + for a specific slot. > > + Bind PCI slot 0001:02:03.4 to pci-stub by: > > + driver[0001:02:03.4]=pci-stub > > > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > > Management. > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > > index 73aef51..7a7ed85 100644 > > --- a/drivers/pci/bus.c > > +++ b/drivers/pci/bus.c > > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > > * are not assigned yet for some devices. > > */ > > pci_fixup_device(pci_fixup_final, dev); > > + pci_device_setup_driver_override(dev); > > pci_create_sysfs_dev_files(dev); > > pci_proc_attach_device(dev); > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index b7678be..0a3e07c 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > > } > > EXPORT_SYMBOL(pci_fixup_cardbus); > > > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > > + > > +struct driver_override_entry { > > + unsigned int domain; > > + unsigned char bus; > > + unsigned int devfn; > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > +}; > > + > > +static struct driver_override_entry __initdata > > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > > +static int driver_override_num_entries __initdata; > > + > > +void pci_device_setup_driver_override(struct pci_dev *dev) > > +{ > > + int i; > > + > > + for (i = 0; i < driver_override_num_entries; i++) { > > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > > + dev->bus->number != driver_override_map[i].bus || > > + dev->devfn != driver_override_map[i].devfn) > > + continue; > > + > > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > > + DRIVER_OVERRIDE_NAME_LENGTH, > > + GFP_KERNEL); > > Hi, > You allocate this entry but never free it? Is being freed in pci_release_dev function. > Shouldn't allocation failure be handled in some way? I thought about it, but in my opinion there is no need for error handling in this situation. - On the worst case scenario it will load the regular driver, no harm done. (kstrndup will return NULL) - It is used in pci_bus_add_device workflow that has no error flow that I am aware of, and even if it were an error flow, in my opinion this is not enough to stop system boot. But thinking of this again, maybe a pr_err message? Your review is most appreciated. Thanks, Marcel > > > + break; > > + } > > +} > > + > > +static void __init pci_parse_driver_override(char *str) > > +{ > > + unsigned int domain, bus, dev, fn; > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > + int ret, next_entry; > > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > > + > > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > > + > > + if (ret != 5) { > > + pr_err("PCI: Invalid command line: driver%s\n", str); > > + return; > > + } > > + > > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > > + return; > > + } > > + > > + next_entry = driver_override_num_entries++; > > + driver_override_map[next_entry].domain = domain; > > + driver_override_map[next_entry].bus = bus && 0xff; > > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > > + memcpy(driver_override_map[next_entry].driver_name, > > + driver_name, sizeof(driver_name)); > > +} > > + > > static int __init pci_setup(char *str) > > { > > while (str) { > > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > > pcie_bus_config = PCIE_BUS_PEER2PEER; > > } else if (!strncmp(str, "pcie_scan_all", 13)) { > > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > > + } else if (!strncmp(str, "driver", 6)) { > > + pci_parse_driver_override(str + 6); > > } else { > > printk(KERN_ERR "PCI: Unknown option `%s'\n", > > str); > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > index 0601890..023d78b 100644 > > --- a/drivers/pci/pci.h > > +++ b/drivers/pci/pci.h > > @@ -197,6 +197,7 @@ enum pci_bar_type { > > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > > int crs_timeout); > > int pci_setup_device(struct pci_dev *dev); > > +void pci_device_setup_driver_override(struct pci_dev *dev); > > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > > struct resource *res, unsigned int reg); > > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > > -- > > 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Oct 01, 2014 at 10:06:46AM +0300, Marcel Apfelbaum wrote: > On Wed, 2014-10-01 at 09:52 +0300, Michael S. Tsirkin wrote: > > On Tue, Sep 30, 2014 at 07:38:35PM +0300, Marcel Apfelbaum wrote: > > > Scanning a lot of devices during boot requires a lot of time. > > > On other scenarios there is a need to bind a driver to a specific slot. > > > > > > Binding devices to pci-stub driver does not work, > > > as it will not differentiate between devices of the > > > same type. Using some start scripts is error prone. > > > > > > The solution leverages driver_override functionality introduced by > > > > > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > > > Author: Alex Williamson <alex.williamson@redhat.com> > > > Date: Tue May 20 08:53:21 2014 -0600 > > > > > > PCI: Introduce new device binding path using pci_dev.driver_override > > > > > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > > > driver[0001:02:03.4]=pci-stub > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > > > --- > > > Notes: > > > - For the moment only 32 slots can be assigned specific driver. > > > - I have further ideas on top of this patch based on your reviews. > > > I thought of: > > > - Use wildcards to specify entire buses/devices, something like: > > > driver[0001:02:*.*]=pci-stub > > > - Use comma to separate several devices: > > > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > > > - Make domain optional: > > > driver[00:03.0]=pci-stub > > > > > > Comments will be appreciated, > > > Thanks, > > > Marcel > > > > > > Documentation/kernel-parameters.txt | 4 +++ > > > drivers/pci/bus.c | 1 + > > > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > > > drivers/pci/pci.h | 1 + > > > 4 files changed, 67 insertions(+) > > > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > > index 5ae8608..c1cbb4c 100644 > > > --- a/Documentation/kernel-parameters.txt > > > +++ b/Documentation/kernel-parameters.txt > > > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > > pcie_scan_all Scan all possible PCIe devices. Otherwise we > > > only look for one device below a PCIe downstream > > > port. > > > + driver Provide an override to the devid<->driver mapping > > > + for a specific slot. > > > + Bind PCI slot 0001:02:03.4 to pci-stub by: > > > + driver[0001:02:03.4]=pci-stub > > > > > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > > > Management. > > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > > > index 73aef51..7a7ed85 100644 > > > --- a/drivers/pci/bus.c > > > +++ b/drivers/pci/bus.c > > > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > > > * are not assigned yet for some devices. > > > */ > > > pci_fixup_device(pci_fixup_final, dev); > > > + pci_device_setup_driver_override(dev); > > > pci_create_sysfs_dev_files(dev); > > > pci_proc_attach_device(dev); > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > index b7678be..0a3e07c 100644 > > > --- a/drivers/pci/pci.c > > > +++ b/drivers/pci/pci.c > > > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > > > } > > > EXPORT_SYMBOL(pci_fixup_cardbus); > > > > > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > > > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > > > + > > > +struct driver_override_entry { > > > + unsigned int domain; > > > + unsigned char bus; > > > + unsigned int devfn; > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > +}; > > > + > > > +static struct driver_override_entry __initdata > > > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > > > +static int driver_override_num_entries __initdata; > > > + > > > +void pci_device_setup_driver_override(struct pci_dev *dev) > > > +{ > > > + int i; > > > + > > > + for (i = 0; i < driver_override_num_entries; i++) { > > > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > > > + dev->bus->number != driver_override_map[i].bus || > > > + dev->devfn != driver_override_map[i].devfn) > > > + continue; > > > + > > > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > > > + DRIVER_OVERRIDE_NAME_LENGTH, > > > + GFP_KERNEL); > > > > > Hi, > > > You allocate this entry but never free it? > Is being freed in pci_release_dev function. > > > Shouldn't allocation failure be handled in some way? > I thought about it, but in my opinion there is no need for error > handling in this situation. > - On the worst case scenario it will load the regular driver, no harm done. > (kstrndup will return NULL) > - It is used in pci_bus_add_device workflow that has no error flow > that I am aware of, and even if it were an error flow, in my opinion > this is not enough to stop system boot. > But thinking of this again, maybe a pr_err message? > > Your review is most appreciated. > Thanks, > Marcel > > Thinking more about it, how about just using strstr to search a string of overrides? This will completely remove the artificial DRIVER_OVERRIDE_MAP_SIZE as well. > > > > > + break; > > > + } > > > +} > > > + > > > +static void __init pci_parse_driver_override(char *str) > > > +{ > > > + unsigned int domain, bus, dev, fn; > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > + int ret, next_entry; > > > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > > > + > > > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > > > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > > > + > > > + if (ret != 5) { > > > + pr_err("PCI: Invalid command line: driver%s\n", str); > > > + return; > > > + } > > > + > > > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > > > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > > > + return; > > > + } > > > + > > > + next_entry = driver_override_num_entries++; > > > + driver_override_map[next_entry].domain = domain; > > > + driver_override_map[next_entry].bus = bus && 0xff; > > > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > > > + memcpy(driver_override_map[next_entry].driver_name, > > > + driver_name, sizeof(driver_name)); > > > +} > > > + > > > static int __init pci_setup(char *str) > > > { > > > while (str) { > > > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > > > pcie_bus_config = PCIE_BUS_PEER2PEER; > > > } else if (!strncmp(str, "pcie_scan_all", 13)) { > > > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > > > + } else if (!strncmp(str, "driver", 6)) { > > > + pci_parse_driver_override(str + 6); > > > } else { > > > printk(KERN_ERR "PCI: Unknown option `%s'\n", > > > str); > > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > > index 0601890..023d78b 100644 > > > --- a/drivers/pci/pci.h > > > +++ b/drivers/pci/pci.h > > > @@ -197,6 +197,7 @@ enum pci_bar_type { > > > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > > > int crs_timeout); > > > int pci_setup_device(struct pci_dev *dev); > > > +void pci_device_setup_driver_override(struct pci_dev *dev); > > > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > > > struct resource *res, unsigned int reg); > > > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > > > -- > > > 1.8.3.1 > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2014-10-01 at 10:30 +0300, Michael S. Tsirkin wrote: > On Wed, Oct 01, 2014 at 10:06:46AM +0300, Marcel Apfelbaum wrote: > > On Wed, 2014-10-01 at 09:52 +0300, Michael S. Tsirkin wrote: > > > On Tue, Sep 30, 2014 at 07:38:35PM +0300, Marcel Apfelbaum wrote: > > > > Scanning a lot of devices during boot requires a lot of time. > > > > On other scenarios there is a need to bind a driver to a specific slot. > > > > > > > > Binding devices to pci-stub driver does not work, > > > > as it will not differentiate between devices of the > > > > same type. Using some start scripts is error prone. > > > > > > > > The solution leverages driver_override functionality introduced by > > > > > > > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > > > > Author: Alex Williamson <alex.williamson@redhat.com> > > > > Date: Tue May 20 08:53:21 2014 -0600 > > > > > > > > PCI: Introduce new device binding path using pci_dev.driver_override > > > > > > > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > > > > driver[0001:02:03.4]=pci-stub > > > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > > > > --- > > > > Notes: > > > > - For the moment only 32 slots can be assigned specific driver. > > > > - I have further ideas on top of this patch based on your reviews. > > > > I thought of: > > > > - Use wildcards to specify entire buses/devices, something like: > > > > driver[0001:02:*.*]=pci-stub > > > > - Use comma to separate several devices: > > > > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > > > > - Make domain optional: > > > > driver[00:03.0]=pci-stub > > > > > > > > Comments will be appreciated, > > > > Thanks, > > > > Marcel > > > > > > > > Documentation/kernel-parameters.txt | 4 +++ > > > > drivers/pci/bus.c | 1 + > > > > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > > > > drivers/pci/pci.h | 1 + > > > > 4 files changed, 67 insertions(+) > > > > > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > > > index 5ae8608..c1cbb4c 100644 > > > > --- a/Documentation/kernel-parameters.txt > > > > +++ b/Documentation/kernel-parameters.txt > > > > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > > > pcie_scan_all Scan all possible PCIe devices. Otherwise we > > > > only look for one device below a PCIe downstream > > > > port. > > > > + driver Provide an override to the devid<->driver mapping > > > > + for a specific slot. > > > > + Bind PCI slot 0001:02:03.4 to pci-stub by: > > > > + driver[0001:02:03.4]=pci-stub > > > > > > > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > > > > Management. > > > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > > > > index 73aef51..7a7ed85 100644 > > > > --- a/drivers/pci/bus.c > > > > +++ b/drivers/pci/bus.c > > > > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > > > > * are not assigned yet for some devices. > > > > */ > > > > pci_fixup_device(pci_fixup_final, dev); > > > > + pci_device_setup_driver_override(dev); > > > > pci_create_sysfs_dev_files(dev); > > > > pci_proc_attach_device(dev); > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > index b7678be..0a3e07c 100644 > > > > --- a/drivers/pci/pci.c > > > > +++ b/drivers/pci/pci.c > > > > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > > > > } > > > > EXPORT_SYMBOL(pci_fixup_cardbus); > > > > > > > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > > > > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > > > > + > > > > +struct driver_override_entry { > > > > + unsigned int domain; > > > > + unsigned char bus; > > > > + unsigned int devfn; > > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > > +}; > > > > + > > > > +static struct driver_override_entry __initdata > > > > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > > > > +static int driver_override_num_entries __initdata; > > > > + > > > > +void pci_device_setup_driver_override(struct pci_dev *dev) > > > > +{ > > > > + int i; > > > > + > > > > + for (i = 0; i < driver_override_num_entries; i++) { > > > > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > > > > + dev->bus->number != driver_override_map[i].bus || > > > > + dev->devfn != driver_override_map[i].devfn) > > > > + continue; > > > > + > > > > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > > > > + DRIVER_OVERRIDE_NAME_LENGTH, > > > > + GFP_KERNEL); > > > > > > > > Hi, > > > > > You allocate this entry but never free it? > > Is being freed in pci_release_dev function. > > > > > Shouldn't allocation failure be handled in some way? > > I thought about it, but in my opinion there is no need for error > > handling in this situation. > > - On the worst case scenario it will load the regular driver, no harm done. > > (kstrndup will return NULL) > > - It is used in pci_bus_add_device workflow that has no error flow > > that I am aware of, and even if it were an error flow, in my opinion > > this is not enough to stop system boot. > > But thinking of this again, maybe a pr_err message? > > > > Your review is most appreciated. > > Thanks, > > Marcel > > > > > > Thinking more about it, how about just using strstr to search a string > of overrides? This will completely remove the artificial > DRIVER_OVERRIDE_MAP_SIZE as well. I'll try it, thanks, hope it will not be too ugly. I will still need to reserve a COMMAND_LINE_SIZE string for "string of overrides", right? Or can I dynamically allocate a buffer to hold the string so early in boot process? If I can, it will be no problem to create a dynamic sized driver_override_map. Thanks for the help, Marcel > > > > > > > > > > > + break; > > > > + } > > > > +} > > > > + > > > > +static void __init pci_parse_driver_override(char *str) > > > > +{ > > > > + unsigned int domain, bus, dev, fn; > > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > > + int ret, next_entry; > > > > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > > > > + > > > > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > > > > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > > > > + > > > > + if (ret != 5) { > > > > + pr_err("PCI: Invalid command line: driver%s\n", str); > > > > + return; > > > > + } > > > > + > > > > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > > > > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > > > > + return; > > > > + } > > > > + > > > > + next_entry = driver_override_num_entries++; > > > > + driver_override_map[next_entry].domain = domain; > > > > + driver_override_map[next_entry].bus = bus && 0xff; > > > > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > > > > + memcpy(driver_override_map[next_entry].driver_name, > > > > + driver_name, sizeof(driver_name)); > > > > +} > > > > + > > > > static int __init pci_setup(char *str) > > > > { > > > > while (str) { > > > > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > > > > pcie_bus_config = PCIE_BUS_PEER2PEER; > > > > } else if (!strncmp(str, "pcie_scan_all", 13)) { > > > > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > > > > + } else if (!strncmp(str, "driver", 6)) { > > > > + pci_parse_driver_override(str + 6); > > > > } else { > > > > printk(KERN_ERR "PCI: Unknown option `%s'\n", > > > > str); > > > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > > > index 0601890..023d78b 100644 > > > > --- a/drivers/pci/pci.h > > > > +++ b/drivers/pci/pci.h > > > > @@ -197,6 +197,7 @@ enum pci_bar_type { > > > > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > > > > int crs_timeout); > > > > int pci_setup_device(struct pci_dev *dev); > > > > +void pci_device_setup_driver_override(struct pci_dev *dev); > > > > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > > > > struct resource *res, unsigned int reg); > > > > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > > > > -- > > > > 1.8.3.1 > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 2014-09-30 at 19:38 +0300, Marcel Apfelbaum wrote: > Scanning a lot of devices during boot requires a lot of time. > On other scenarios there is a need to bind a driver to a specific slot. > > Binding devices to pci-stub driver does not work, > as it will not differentiate between devices of the > same type. Using some start scripts is error prone. > > The solution leverages driver_override functionality introduced by > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > Author: Alex Williamson <alex.williamson@redhat.com> > Date: Tue May 20 08:53:21 2014 -0600 > > PCI: Introduce new device binding path using pci_dev.driver_override > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > driver[0001:02:03.4]=pci-stub So the option is actually: pci=driver=[...]=foo,driver=[...]=bar That's not very clear from the commit log. > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > --- > Notes: > - For the moment only 32 slots can be assigned specific driver. > - I have further ideas on top of this patch based on your reviews. > I thought of: > - Use wildcards to specify entire buses/devices, something like: > driver[0001:02:*.*]=pci-stub > - Use comma to separate several devices: > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > - Make domain optional: > driver[00:03.0]=pci-stub > > Comments will be appreciated, > Thanks, > Marcel > > Documentation/kernel-parameters.txt | 4 +++ > drivers/pci/bus.c | 1 + > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > drivers/pci/pci.h | 1 + > 4 files changed, 67 insertions(+) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 5ae8608..c1cbb4c 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > pcie_scan_all Scan all possible PCIe devices. Otherwise we > only look for one device below a PCIe downstream > port. > + driver Provide an override to the devid<->driver mapping > + for a specific slot. > + Bind PCI slot 0001:02:03.4 to pci-stub by: > + driver[0001:02:03.4]=pci-stub > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > Management. > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > index 73aef51..7a7ed85 100644 > --- a/drivers/pci/bus.c > +++ b/drivers/pci/bus.c > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > * are not assigned yet for some devices. > */ > pci_fixup_device(pci_fixup_final, dev); > + pci_device_setup_driver_override(dev); > pci_create_sysfs_dev_files(dev); > pci_proc_attach_device(dev); > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index b7678be..0a3e07c 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > } > EXPORT_SYMBOL(pci_fixup_cardbus); > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > + > +struct driver_override_entry { > + unsigned int domain; u16 > + unsigned char bus; u8 > + unsigned int devfn; u8 > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > +}; > + > +static struct driver_override_entry __initdata > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > +static int driver_override_num_entries __initdata; > + > +void pci_device_setup_driver_override(struct pci_dev *dev) > +{ > + int i; > + > + for (i = 0; i < driver_override_num_entries; i++) { > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > + dev->bus->number != driver_override_map[i].bus || > + dev->devfn != driver_override_map[i].devfn) > + continue; > + > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > + DRIVER_OVERRIDE_NAME_LENGTH, > + GFP_KERNEL); > + break; > + } > +} > + > +static void __init pci_parse_driver_override(char *str) > +{ > + unsigned int domain, bus, dev, fn; > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > + int ret, next_entry; > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > + > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); There must be a less confusing way to do this. > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > + > + if (ret != 5) { > + pr_err("PCI: Invalid command line: driver%s\n", str); > + return; > + } > + > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > + return; > + } > + > + next_entry = driver_override_num_entries++; > + driver_override_map[next_entry].domain = domain; > + driver_override_map[next_entry].bus = bus && 0xff; How could it not be given our format? > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); PCI_DEVFN(dev, fn) > + memcpy(driver_override_map[next_entry].driver_name, > + driver_name, sizeof(driver_name)); > +} > + > static int __init pci_setup(char *str) > { > while (str) { > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > pcie_bus_config = PCIE_BUS_PEER2PEER; > } else if (!strncmp(str, "pcie_scan_all", 13)) { > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > + } else if (!strncmp(str, "driver", 6)) { > + pci_parse_driver_override(str + 6); > } else { > printk(KERN_ERR "PCI: Unknown option `%s'\n", > str); > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 0601890..023d78b 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -197,6 +197,7 @@ enum pci_bar_type { > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > int crs_timeout); > int pci_setup_device(struct pci_dev *dev); > +void pci_device_setup_driver_override(struct pci_dev *dev); > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > struct resource *res, unsigned int reg); > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2014-10-01 at 10:50 +0300, Marcel Apfelbaum wrote: > On Wed, 2014-10-01 at 10:30 +0300, Michael S. Tsirkin wrote: > > On Wed, Oct 01, 2014 at 10:06:46AM +0300, Marcel Apfelbaum wrote: > > > On Wed, 2014-10-01 at 09:52 +0300, Michael S. Tsirkin wrote: > > > > On Tue, Sep 30, 2014 at 07:38:35PM +0300, Marcel Apfelbaum wrote: > > > > > Scanning a lot of devices during boot requires a lot of time. > > > > > On other scenarios there is a need to bind a driver to a specific slot. > > > > > > > > > > Binding devices to pci-stub driver does not work, > > > > > as it will not differentiate between devices of the > > > > > same type. Using some start scripts is error prone. > > > > > > > > > > The solution leverages driver_override functionality introduced by > > > > > > > > > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > > > > > Author: Alex Williamson <alex.williamson@redhat.com> > > > > > Date: Tue May 20 08:53:21 2014 -0600 > > > > > > > > > > PCI: Introduce new device binding path using pci_dev.driver_override > > > > > > > > > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > > > > > driver[0001:02:03.4]=pci-stub > > > > > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > > > > > --- > > > > > Notes: > > > > > - For the moment only 32 slots can be assigned specific driver. > > > > > - I have further ideas on top of this patch based on your reviews. > > > > > I thought of: > > > > > - Use wildcards to specify entire buses/devices, something like: > > > > > driver[0001:02:*.*]=pci-stub > > > > > - Use comma to separate several devices: > > > > > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > > > > > - Make domain optional: > > > > > driver[00:03.0]=pci-stub > > > > > > > > > > Comments will be appreciated, > > > > > Thanks, > > > > > Marcel > > > > > > > > > > Documentation/kernel-parameters.txt | 4 +++ > > > > > drivers/pci/bus.c | 1 + > > > > > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > > > > > drivers/pci/pci.h | 1 + > > > > > 4 files changed, 67 insertions(+) > > > > > > > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > > > > index 5ae8608..c1cbb4c 100644 > > > > > --- a/Documentation/kernel-parameters.txt > > > > > +++ b/Documentation/kernel-parameters.txt > > > > > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > > > > pcie_scan_all Scan all possible PCIe devices. Otherwise we > > > > > only look for one device below a PCIe downstream > > > > > port. > > > > > + driver Provide an override to the devid<->driver mapping > > > > > + for a specific slot. > > > > > + Bind PCI slot 0001:02:03.4 to pci-stub by: > > > > > + driver[0001:02:03.4]=pci-stub > > > > > > > > > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > > > > > Management. > > > > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > > > > > index 73aef51..7a7ed85 100644 > > > > > --- a/drivers/pci/bus.c > > > > > +++ b/drivers/pci/bus.c > > > > > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > > > > > * are not assigned yet for some devices. > > > > > */ > > > > > pci_fixup_device(pci_fixup_final, dev); > > > > > + pci_device_setup_driver_override(dev); > > > > > pci_create_sysfs_dev_files(dev); > > > > > pci_proc_attach_device(dev); > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > index b7678be..0a3e07c 100644 > > > > > --- a/drivers/pci/pci.c > > > > > +++ b/drivers/pci/pci.c > > > > > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > > > > > } > > > > > EXPORT_SYMBOL(pci_fixup_cardbus); > > > > > > > > > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > > > > > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > > > > > + > > > > > +struct driver_override_entry { > > > > > + unsigned int domain; > > > > > + unsigned char bus; > > > > > + unsigned int devfn; > > > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > > > +}; > > > > > + > > > > > +static struct driver_override_entry __initdata > > > > > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > > > > > +static int driver_override_num_entries __initdata; > > > > > + > > > > > +void pci_device_setup_driver_override(struct pci_dev *dev) > > > > > +{ > > > > > + int i; > > > > > + > > > > > + for (i = 0; i < driver_override_num_entries; i++) { > > > > > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > > > > > + dev->bus->number != driver_override_map[i].bus || > > > > > + dev->devfn != driver_override_map[i].devfn) > > > > > + continue; > > > > > + > > > > > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > > > > > + DRIVER_OVERRIDE_NAME_LENGTH, > > > > > + GFP_KERNEL); > > > > > > > > > > > Hi, > > > > > > > You allocate this entry but never free it? > > > Is being freed in pci_release_dev function. > > > > > > > Shouldn't allocation failure be handled in some way? > > > I thought about it, but in my opinion there is no need for error > > > handling in this situation. > > > - On the worst case scenario it will load the regular driver, no harm done. > > > (kstrndup will return NULL) > > > - It is used in pci_bus_add_device workflow that has no error flow > > > that I am aware of, and even if it were an error flow, in my opinion > > > this is not enough to stop system boot. > > > But thinking of this again, maybe a pr_err message? > > > > > > Your review is most appreciated. > > > Thanks, > > > Marcel > > > > > > > > > > Thinking more about it, how about just using strstr to search a string > > of overrides? This will completely remove the artificial > > DRIVER_OVERRIDE_MAP_SIZE as well. > I'll try it, thanks, hope it will not be too ugly. > > I will still need to reserve a COMMAND_LINE_SIZE string for "string of overrides", right? > Or can I dynamically allocate a buffer to hold the string so early in boot process? > If I can, it will be no problem to create a dynamic sized driver_override_map. I think Michael is suggesting searching the existing commandline on each pass so that you don't need to allocate any memory at all. Thanks, Alex > > > > > > > > > + break; > > > > > + } > > > > > +} > > > > > + > > > > > +static void __init pci_parse_driver_override(char *str) > > > > > +{ > > > > > + unsigned int domain, bus, dev, fn; > > > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > > > + int ret, next_entry; > > > > > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > > > > > + > > > > > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > > > > > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > > > > > + > > > > > + if (ret != 5) { > > > > > + pr_err("PCI: Invalid command line: driver%s\n", str); > > > > > + return; > > > > > + } > > > > > + > > > > > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > > > > > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > > > > > + return; > > > > > + } > > > > > + > > > > > + next_entry = driver_override_num_entries++; > > > > > + driver_override_map[next_entry].domain = domain; > > > > > + driver_override_map[next_entry].bus = bus && 0xff; > > > > > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > > > > > + memcpy(driver_override_map[next_entry].driver_name, > > > > > + driver_name, sizeof(driver_name)); > > > > > +} > > > > > + > > > > > static int __init pci_setup(char *str) > > > > > { > > > > > while (str) { > > > > > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > > > > > pcie_bus_config = PCIE_BUS_PEER2PEER; > > > > > } else if (!strncmp(str, "pcie_scan_all", 13)) { > > > > > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > > > > > + } else if (!strncmp(str, "driver", 6)) { > > > > > + pci_parse_driver_override(str + 6); > > > > > } else { > > > > > printk(KERN_ERR "PCI: Unknown option `%s'\n", > > > > > str); > > > > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > > > > index 0601890..023d78b 100644 > > > > > --- a/drivers/pci/pci.h > > > > > +++ b/drivers/pci/pci.h > > > > > @@ -197,6 +197,7 @@ enum pci_bar_type { > > > > > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > > > > > int crs_timeout); > > > > > int pci_setup_device(struct pci_dev *dev); > > > > > +void pci_device_setup_driver_override(struct pci_dev *dev); > > > > > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > > > > > struct resource *res, unsigned int reg); > > > > > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > > > > > -- > > > > > 1.8.3.1 > > > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2014-10-01 at 12:48 -0600, Alex Williamson wrote: > On Tue, 2014-09-30 at 19:38 +0300, Marcel Apfelbaum wrote: > > Scanning a lot of devices during boot requires a lot of time. > > On other scenarios there is a need to bind a driver to a specific slot. > > > > Binding devices to pci-stub driver does not work, > > as it will not differentiate between devices of the > > same type. Using some start scripts is error prone. > > > > The solution leverages driver_override functionality introduced by > > > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > > Author: Alex Williamson <alex.williamson@redhat.com> > > Date: Tue May 20 08:53:21 2014 -0600 > > > > PCI: Introduce new device binding path using pci_dev.driver_override > > > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > > driver[0001:02:03.4]=pci-stub > > So the option is actually: > > pci=driver=[...]=foo,driver=[...]=bar > > That's not very clear from the commit log. Hi, I will make it more clear. Thanks for the review, Marcel > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > > --- > > Notes: > > - For the moment only 32 slots can be assigned specific driver. > > - I have further ideas on top of this patch based on your reviews. > > I thought of: > > - Use wildcards to specify entire buses/devices, something like: > > driver[0001:02:*.*]=pci-stub > > - Use comma to separate several devices: > > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > > - Make domain optional: > > driver[00:03.0]=pci-stub > > > > Comments will be appreciated, > > Thanks, > > Marcel > > > > Documentation/kernel-parameters.txt | 4 +++ > > drivers/pci/bus.c | 1 + > > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > > drivers/pci/pci.h | 1 + > > 4 files changed, 67 insertions(+) > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > index 5ae8608..c1cbb4c 100644 > > --- a/Documentation/kernel-parameters.txt > > +++ b/Documentation/kernel-parameters.txt > > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > pcie_scan_all Scan all possible PCIe devices. Otherwise we > > only look for one device below a PCIe downstream > > port. > > + driver Provide an override to the devid<->driver mapping > > + for a specific slot. > > + Bind PCI slot 0001:02:03.4 to pci-stub by: > > + driver[0001:02:03.4]=pci-stub > > > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > > Management. > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > > index 73aef51..7a7ed85 100644 > > --- a/drivers/pci/bus.c > > +++ b/drivers/pci/bus.c > > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > > * are not assigned yet for some devices. > > */ > > pci_fixup_device(pci_fixup_final, dev); > > + pci_device_setup_driver_override(dev); > > pci_create_sysfs_dev_files(dev); > > pci_proc_attach_device(dev); > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index b7678be..0a3e07c 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > > } > > EXPORT_SYMBOL(pci_fixup_cardbus); > > > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > > + > > +struct driver_override_entry { > > + unsigned int domain; > > u16 > > > + unsigned char bus; > > u8 > > > + unsigned int devfn; > > u8 > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > +}; > > + > > +static struct driver_override_entry __initdata > > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > > +static int driver_override_num_entries __initdata; > > + > > +void pci_device_setup_driver_override(struct pci_dev *dev) > > +{ > > + int i; > > + > > + for (i = 0; i < driver_override_num_entries; i++) { > > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > > + dev->bus->number != driver_override_map[i].bus || > > + dev->devfn != driver_override_map[i].devfn) > > + continue; > > + > > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > > + DRIVER_OVERRIDE_NAME_LENGTH, > > + GFP_KERNEL); > > + break; > > + } > > +} > > + > > +static void __init pci_parse_driver_override(char *str) > > +{ > > + unsigned int domain, bus, dev, fn; > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > + int ret, next_entry; > > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > > + > > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > > There must be a less confusing way to do this. > > > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > > + > > + if (ret != 5) { > > + pr_err("PCI: Invalid command line: driver%s\n", str); > > + return; > > + } > > + > > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > > + return; > > + } > > + > > + next_entry = driver_override_num_entries++; > > + driver_override_map[next_entry].domain = domain; > > + driver_override_map[next_entry].bus = bus && 0xff; > > How could it not be given our format? > > > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > > PCI_DEVFN(dev, fn) > > > + memcpy(driver_override_map[next_entry].driver_name, > > + driver_name, sizeof(driver_name)); > > +} > > + > > static int __init pci_setup(char *str) > > { > > while (str) { > > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > > pcie_bus_config = PCIE_BUS_PEER2PEER; > > } else if (!strncmp(str, "pcie_scan_all", 13)) { > > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > > + } else if (!strncmp(str, "driver", 6)) { > > + pci_parse_driver_override(str + 6); > > } else { > > printk(KERN_ERR "PCI: Unknown option `%s'\n", > > str); > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > index 0601890..023d78b 100644 > > --- a/drivers/pci/pci.h > > +++ b/drivers/pci/pci.h > > @@ -197,6 +197,7 @@ enum pci_bar_type { > > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > > int crs_timeout); > > int pci_setup_device(struct pci_dev *dev); > > +void pci_device_setup_driver_override(struct pci_dev *dev); > > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > > struct resource *res, unsigned int reg); > > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Oct 01, 2014 at 12:51:03PM -0600, Alex Williamson wrote: > On Wed, 2014-10-01 at 10:50 +0300, Marcel Apfelbaum wrote: > > On Wed, 2014-10-01 at 10:30 +0300, Michael S. Tsirkin wrote: > > > On Wed, Oct 01, 2014 at 10:06:46AM +0300, Marcel Apfelbaum wrote: > > > > On Wed, 2014-10-01 at 09:52 +0300, Michael S. Tsirkin wrote: > > > > > On Tue, Sep 30, 2014 at 07:38:35PM +0300, Marcel Apfelbaum wrote: > > > > > > Scanning a lot of devices during boot requires a lot of time. > > > > > > On other scenarios there is a need to bind a driver to a specific slot. > > > > > > > > > > > > Binding devices to pci-stub driver does not work, > > > > > > as it will not differentiate between devices of the > > > > > > same type. Using some start scripts is error prone. > > > > > > > > > > > > The solution leverages driver_override functionality introduced by > > > > > > > > > > > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > > > > > > Author: Alex Williamson <alex.williamson@redhat.com> > > > > > > Date: Tue May 20 08:53:21 2014 -0600 > > > > > > > > > > > > PCI: Introduce new device binding path using pci_dev.driver_override > > > > > > > > > > > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > > > > > > driver[0001:02:03.4]=pci-stub > > > > > > > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > > > > > > --- > > > > > > Notes: > > > > > > - For the moment only 32 slots can be assigned specific driver. > > > > > > - I have further ideas on top of this patch based on your reviews. > > > > > > I thought of: > > > > > > - Use wildcards to specify entire buses/devices, something like: > > > > > > driver[0001:02:*.*]=pci-stub > > > > > > - Use comma to separate several devices: > > > > > > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > > > > > > - Make domain optional: > > > > > > driver[00:03.0]=pci-stub > > > > > > > > > > > > Comments will be appreciated, > > > > > > Thanks, > > > > > > Marcel > > > > > > > > > > > > Documentation/kernel-parameters.txt | 4 +++ > > > > > > drivers/pci/bus.c | 1 + > > > > > > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > > > > > > drivers/pci/pci.h | 1 + > > > > > > 4 files changed, 67 insertions(+) > > > > > > > > > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > > > > > index 5ae8608..c1cbb4c 100644 > > > > > > --- a/Documentation/kernel-parameters.txt > > > > > > +++ b/Documentation/kernel-parameters.txt > > > > > > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > > > > > pcie_scan_all Scan all possible PCIe devices. Otherwise we > > > > > > only look for one device below a PCIe downstream > > > > > > port. > > > > > > + driver Provide an override to the devid<->driver mapping > > > > > > + for a specific slot. > > > > > > + Bind PCI slot 0001:02:03.4 to pci-stub by: > > > > > > + driver[0001:02:03.4]=pci-stub > > > > > > > > > > > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > > > > > > Management. > > > > > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > > > > > > index 73aef51..7a7ed85 100644 > > > > > > --- a/drivers/pci/bus.c > > > > > > +++ b/drivers/pci/bus.c > > > > > > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > > > > > > * are not assigned yet for some devices. > > > > > > */ > > > > > > pci_fixup_device(pci_fixup_final, dev); > > > > > > + pci_device_setup_driver_override(dev); > > > > > > pci_create_sysfs_dev_files(dev); > > > > > > pci_proc_attach_device(dev); > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > index b7678be..0a3e07c 100644 > > > > > > --- a/drivers/pci/pci.c > > > > > > +++ b/drivers/pci/pci.c > > > > > > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > > > > > > } > > > > > > EXPORT_SYMBOL(pci_fixup_cardbus); > > > > > > > > > > > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > > > > > > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > > > > > > + > > > > > > +struct driver_override_entry { > > > > > > + unsigned int domain; > > > > > > + unsigned char bus; > > > > > > + unsigned int devfn; > > > > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > > > > +}; > > > > > > + > > > > > > +static struct driver_override_entry __initdata > > > > > > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > > > > > > +static int driver_override_num_entries __initdata; > > > > > > + > > > > > > +void pci_device_setup_driver_override(struct pci_dev *dev) > > > > > > +{ > > > > > > + int i; > > > > > > + > > > > > > + for (i = 0; i < driver_override_num_entries; i++) { > > > > > > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > > > > > > + dev->bus->number != driver_override_map[i].bus || > > > > > > + dev->devfn != driver_override_map[i].devfn) > > > > > > + continue; > > > > > > + > > > > > > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > > > > > > + DRIVER_OVERRIDE_NAME_LENGTH, > > > > > > + GFP_KERNEL); > > > > > > > > > > > > > > Hi, > > > > > > > > > You allocate this entry but never free it? > > > > Is being freed in pci_release_dev function. > > > > > > > > > Shouldn't allocation failure be handled in some way? > > > > I thought about it, but in my opinion there is no need for error > > > > handling in this situation. > > > > - On the worst case scenario it will load the regular driver, no harm done. > > > > (kstrndup will return NULL) > > > > - It is used in pci_bus_add_device workflow that has no error flow > > > > that I am aware of, and even if it were an error flow, in my opinion > > > > this is not enough to stop system boot. > > > > But thinking of this again, maybe a pr_err message? > > > > > > > > Your review is most appreciated. > > > > Thanks, > > > > Marcel > > > > > > > > > > > > > > Thinking more about it, how about just using strstr to search a string > > > of overrides? This will completely remove the artificial > > > DRIVER_OVERRIDE_MAP_SIZE as well. > > I'll try it, thanks, hope it will not be too ugly. > > > > I will still need to reserve a COMMAND_LINE_SIZE string for "string of overrides", right? > > Or can I dynamically allocate a buffer to hold the string so early in boot process? > > If I can, it will be no problem to create a dynamic sized driver_override_map. > > I think Michael is suggesting searching the existing commandline on each > pass so that you don't need to allocate any memory at all. Thanks, > > Alex Conditional on having the option specified. BTW, API-wise, I think that it's a good idea to make the fact that pci addresses are used, explicit. > > > > > > > > > > > + break; > > > > > > + } > > > > > > +} > > > > > > + > > > > > > +static void __init pci_parse_driver_override(char *str) > > > > > > +{ > > > > > > + unsigned int domain, bus, dev, fn; > > > > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > > > > + int ret, next_entry; > > > > > > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > > > > > > + > > > > > > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > > > > > > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > > > > > > + > > > > > > + if (ret != 5) { > > > > > > + pr_err("PCI: Invalid command line: driver%s\n", str); > > > > > > + return; > > > > > > + } > > > > > > + > > > > > > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > > > > > > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > > > > > > + return; > > > > > > + } > > > > > > + > > > > > > + next_entry = driver_override_num_entries++; > > > > > > + driver_override_map[next_entry].domain = domain; > > > > > > + driver_override_map[next_entry].bus = bus && 0xff; > > > > > > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > > > > > > + memcpy(driver_override_map[next_entry].driver_name, > > > > > > + driver_name, sizeof(driver_name)); > > > > > > +} > > > > > > + > > > > > > static int __init pci_setup(char *str) > > > > > > { > > > > > > while (str) { > > > > > > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > > > > > > pcie_bus_config = PCIE_BUS_PEER2PEER; > > > > > > } else if (!strncmp(str, "pcie_scan_all", 13)) { > > > > > > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > > > > > > + } else if (!strncmp(str, "driver", 6)) { > > > > > > + pci_parse_driver_override(str + 6); > > > > > > } else { > > > > > > printk(KERN_ERR "PCI: Unknown option `%s'\n", > > > > > > str); > > > > > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > > > > > index 0601890..023d78b 100644 > > > > > > --- a/drivers/pci/pci.h > > > > > > +++ b/drivers/pci/pci.h > > > > > > @@ -197,6 +197,7 @@ enum pci_bar_type { > > > > > > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > > > > > > int crs_timeout); > > > > > > int pci_setup_device(struct pci_dev *dev); > > > > > > +void pci_device_setup_driver_override(struct pci_dev *dev); > > > > > > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > > > > > > struct resource *res, unsigned int reg); > > > > > > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > > > > > > -- > > > > > > 1.8.3.1 > > > > > > > > > > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2014-10-02 at 11:12 +0300, Michael S. Tsirkin wrote: > On Wed, Oct 01, 2014 at 12:51:03PM -0600, Alex Williamson wrote: > > On Wed, 2014-10-01 at 10:50 +0300, Marcel Apfelbaum wrote: > > > On Wed, 2014-10-01 at 10:30 +0300, Michael S. Tsirkin wrote: > > > > On Wed, Oct 01, 2014 at 10:06:46AM +0300, Marcel Apfelbaum wrote: > > > > > On Wed, 2014-10-01 at 09:52 +0300, Michael S. Tsirkin wrote: > > > > > > On Tue, Sep 30, 2014 at 07:38:35PM +0300, Marcel Apfelbaum wrote: > > > > > > > Scanning a lot of devices during boot requires a lot of time. > > > > > > > On other scenarios there is a need to bind a driver to a specific slot. > > > > > > > > > > > > > > Binding devices to pci-stub driver does not work, > > > > > > > as it will not differentiate between devices of the > > > > > > > same type. Using some start scripts is error prone. > > > > > > > > > > > > > > The solution leverages driver_override functionality introduced by > > > > > > > > > > > > > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > > > > > > > Author: Alex Williamson <alex.williamson@redhat.com> > > > > > > > Date: Tue May 20 08:53:21 2014 -0600 > > > > > > > > > > > > > > PCI: Introduce new device binding path using pci_dev.driver_override > > > > > > > > > > > > > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > > > > > > > driver[0001:02:03.4]=pci-stub > > > > > > > > > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> > > > > > > > --- > > > > > > > Notes: > > > > > > > - For the moment only 32 slots can be assigned specific driver. > > > > > > > - I have further ideas on top of this patch based on your reviews. > > > > > > > I thought of: > > > > > > > - Use wildcards to specify entire buses/devices, something like: > > > > > > > driver[0001:02:*.*]=pci-stub > > > > > > > - Use comma to separate several devices: > > > > > > > driver[0001:02:03.4,0001:02:04.0,...]=pci-stub > > > > > > > - Make domain optional: > > > > > > > driver[00:03.0]=pci-stub > > > > > > > > > > > > > > Comments will be appreciated, > > > > > > > Thanks, > > > > > > > Marcel > > > > > > > > > > > > > > Documentation/kernel-parameters.txt | 4 +++ > > > > > > > drivers/pci/bus.c | 1 + > > > > > > > drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ > > > > > > > drivers/pci/pci.h | 1 + > > > > > > > 4 files changed, 67 insertions(+) > > > > > > > > > > > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > > > > > > index 5ae8608..c1cbb4c 100644 > > > > > > > --- a/Documentation/kernel-parameters.txt > > > > > > > +++ b/Documentation/kernel-parameters.txt > > > > > > > @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > > > > > > pcie_scan_all Scan all possible PCIe devices. Otherwise we > > > > > > > only look for one device below a PCIe downstream > > > > > > > port. > > > > > > > + driver Provide an override to the devid<->driver mapping > > > > > > > + for a specific slot. > > > > > > > + Bind PCI slot 0001:02:03.4 to pci-stub by: > > > > > > > + driver[0001:02:03.4]=pci-stub > > > > > > > > > > > > > > pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power > > > > > > > Management. > > > > > > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > > > > > > > index 73aef51..7a7ed85 100644 > > > > > > > --- a/drivers/pci/bus.c > > > > > > > +++ b/drivers/pci/bus.c > > > > > > > @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) > > > > > > > * are not assigned yet for some devices. > > > > > > > */ > > > > > > > pci_fixup_device(pci_fixup_final, dev); > > > > > > > + pci_device_setup_driver_override(dev); > > > > > > > pci_create_sysfs_dev_files(dev); > > > > > > > pci_proc_attach_device(dev); > > > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > > index b7678be..0a3e07c 100644 > > > > > > > --- a/drivers/pci/pci.c > > > > > > > +++ b/drivers/pci/pci.c > > > > > > > @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) > > > > > > > } > > > > > > > EXPORT_SYMBOL(pci_fixup_cardbus); > > > > > > > > > > > > > > +#define DRIVER_OVERRIDE_NAME_LENGTH 64 > > > > > > > +#define DRIVER_OVERRIDE_MAP_SIZE 32 > > > > > > > + > > > > > > > +struct driver_override_entry { > > > > > > > + unsigned int domain; > > > > > > > + unsigned char bus; > > > > > > > + unsigned int devfn; > > > > > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > > > > > +}; > > > > > > > + > > > > > > > +static struct driver_override_entry __initdata > > > > > > > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > > > > > > > +static int driver_override_num_entries __initdata; > > > > > > > + > > > > > > > +void pci_device_setup_driver_override(struct pci_dev *dev) > > > > > > > +{ > > > > > > > + int i; > > > > > > > + > > > > > > > + for (i = 0; i < driver_override_num_entries; i++) { > > > > > > > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > > > > > > > + dev->bus->number != driver_override_map[i].bus || > > > > > > > + dev->devfn != driver_override_map[i].devfn) > > > > > > > + continue; > > > > > > > + > > > > > > > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > > > > > > > + DRIVER_OVERRIDE_NAME_LENGTH, > > > > > > > + GFP_KERNEL); > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > You allocate this entry but never free it? > > > > > Is being freed in pci_release_dev function. > > > > > > > > > > > Shouldn't allocation failure be handled in some way? > > > > > I thought about it, but in my opinion there is no need for error > > > > > handling in this situation. > > > > > - On the worst case scenario it will load the regular driver, no harm done. > > > > > (kstrndup will return NULL) > > > > > - It is used in pci_bus_add_device workflow that has no error flow > > > > > that I am aware of, and even if it were an error flow, in my opinion > > > > > this is not enough to stop system boot. > > > > > But thinking of this again, maybe a pr_err message? > > > > > > > > > > Your review is most appreciated. > > > > > Thanks, > > > > > Marcel > > > > > > > > > > > > > > > > > > Thinking more about it, how about just using strstr to search a string > > > > of overrides? This will completely remove the artificial > > > > DRIVER_OVERRIDE_MAP_SIZE as well. > > > I'll try it, thanks, hope it will not be too ugly. > > > > > > I will still need to reserve a COMMAND_LINE_SIZE string for "string of overrides", right? > > > Or can I dynamically allocate a buffer to hold the string so early in boot process? > > > If I can, it will be no problem to create a dynamic sized driver_override_map. > > > > I think Michael is suggesting searching the existing commandline on each > > pass so that you don't need to allocate any memory at all. Thanks, I thought about doing that, but this would mean too add <linux/bootmem.h> header to drivers/pci/pci.c and it seems too much to expose all of that stuff only for this feature. Please see the alternative bellow. > > > > Alex > > Conditional on having the option specified. > BTW, API-wise, I think that it's a good idea to make the fact that pci > addresses are used, explicit. I am working on a way to use a dynamically allocated list to store the driver/slot matches and in this way we will have: - no need to expose <linux/bootmem.h> to drivers/pci/pci.c - memory will be used if needed and no pre-allocated - no limit for the nr of slots to override. V2 will be sent shortly. Thanks, Marcel > > > > > > > > > > > > > > + break; > > > > > > > + } > > > > > > > +} > > > > > > > + > > > > > > > +static void __init pci_parse_driver_override(char *str) > > > > > > > +{ > > > > > > > + unsigned int domain, bus, dev, fn; > > > > > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > > > > > > + int ret, next_entry; > > > > > > > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > > > > > > > + > > > > > > > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > > > > > > > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > > > > > > > + > > > > > > > + if (ret != 5) { > > > > > > > + pr_err("PCI: Invalid command line: driver%s\n", str); > > > > > > > + return; > > > > > > > + } > > > > > > > + > > > > > > > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > > > > > > > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > > > > > > > + return; > > > > > > > + } > > > > > > > + > > > > > > > + next_entry = driver_override_num_entries++; > > > > > > > + driver_override_map[next_entry].domain = domain; > > > > > > > + driver_override_map[next_entry].bus = bus && 0xff; > > > > > > > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > > > > > > > + memcpy(driver_override_map[next_entry].driver_name, > > > > > > > + driver_name, sizeof(driver_name)); > > > > > > > +} > > > > > > > + > > > > > > > static int __init pci_setup(char *str) > > > > > > > { > > > > > > > while (str) { > > > > > > > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > > > > > > > pcie_bus_config = PCIE_BUS_PEER2PEER; > > > > > > > } else if (!strncmp(str, "pcie_scan_all", 13)) { > > > > > > > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > > > > > > > + } else if (!strncmp(str, "driver", 6)) { > > > > > > > + pci_parse_driver_override(str + 6); > > > > > > > } else { > > > > > > > printk(KERN_ERR "PCI: Unknown option `%s'\n", > > > > > > > str); > > > > > > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > > > > > > index 0601890..023d78b 100644 > > > > > > > --- a/drivers/pci/pci.h > > > > > > > +++ b/drivers/pci/pci.h > > > > > > > @@ -197,6 +197,7 @@ enum pci_bar_type { > > > > > > > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > > > > > > > int crs_timeout); > > > > > > > int pci_setup_device(struct pci_dev *dev); > > > > > > > +void pci_device_setup_driver_override(struct pci_dev *dev); > > > > > > > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > > > > > > > struct resource *res, unsigned int reg); > > > > > > > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > > > > > > > -- > > > > > > > 1.8.3.1 > > > > > > > > > > > > > > > > > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2014-10-01 at 12:48 -0600, Alex Williamson wrote: > On Tue, 2014-09-30 at 19:38 +0300, Marcel Apfelbaum wrote: > > Scanning a lot of devices during boot requires a lot of time. > > On other scenarios there is a need to bind a driver to a specific slot. > > > > Binding devices to pci-stub driver does not work, > > as it will not differentiate between devices of the > > same type. Using some start scripts is error prone. > > > > The solution leverages driver_override functionality introduced by > > > > commit: 782a985d7af26db39e86070d28f987cad21313c0 > > Author: Alex Williamson <alex.williamson@redhat.com> > > Date: Tue May 20 08:53:21 2014 -0600 > > > > PCI: Introduce new device binding path using pci_dev.driver_override > > > > In order to bind PCI slot 0001:02:03.4 to pci-stub use: > > driver[0001:02:03.4]=pci-stub > > So the option is actually: > > pci=driver=[...]=foo,driver=[...]=bar > > That's not very clear from the commit log. > [...] Hi Alex, I am sorry, but I missed the bellow comments, I am going to fix them for the next version. > > + > > +struct driver_override_entry { > > + unsigned int domain; > > u16 Sure > > > + unsigned char bus; > > u8 Sure > > > + unsigned int devfn; > > u8 Sure > > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; I'll allocate it dynamically > > +}; > > + > > +static struct driver_override_entry __initdata > > + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; > > +static int driver_override_num_entries __initdata; > > + > > +void pci_device_setup_driver_override(struct pci_dev *dev) > > +{ > > + int i; > > + > > + for (i = 0; i < driver_override_num_entries; i++) { > > + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || > > + dev->bus->number != driver_override_map[i].bus || > > + dev->devfn != driver_override_map[i].devfn) > > + continue; > > + > > + dev->driver_override = kstrndup(driver_override_map[i].driver_name, > > + DRIVER_OVERRIDE_NAME_LENGTH, > > + GFP_KERNEL); > > + break; > > + } > > +} > > + > > +static void __init pci_parse_driver_override(char *str) > > +{ > > + unsigned int domain, bus, dev, fn; > > + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; > > + int ret, next_entry; > > + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; > > + > > + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); > > There must be a less confusing way to do this. I'll try it, and also I'll get rid of DRIVER_OVERRIDE_NAME_LENGTH restriction. > > > + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); > > + > > + if (ret != 5) { > > + pr_err("PCI: Invalid command line: driver%s\n", str); > > + return; > > + } > > + > > + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { > > + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); > > + return; > > + } > > + > > + next_entry = driver_override_num_entries++; > > + driver_override_map[next_entry].domain = domain; > > + driver_override_map[next_entry].bus = bus && 0xff; > > How could it not be given our format? Right, I'll remove the check. > > > + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); > > PCI_DEVFN(dev, fn) Sure, Thank you for the review, Marcel > > > + memcpy(driver_override_map[next_entry].driver_name, > > + driver_name, sizeof(driver_name)); > > +} > > + > > static int __init pci_setup(char *str) > > { > > while (str) { > > @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) > > pcie_bus_config = PCIE_BUS_PEER2PEER; > > } else if (!strncmp(str, "pcie_scan_all", 13)) { > > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > > + } else if (!strncmp(str, "driver", 6)) { > > + pci_parse_driver_override(str + 6); > > } else { > > printk(KERN_ERR "PCI: Unknown option `%s'\n", > > str); > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > index 0601890..023d78b 100644 > > --- a/drivers/pci/pci.h > > +++ b/drivers/pci/pci.h > > @@ -197,6 +197,7 @@ enum pci_bar_type { > > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > > int crs_timeout); > > int pci_setup_device(struct pci_dev *dev); > > +void pci_device_setup_driver_override(struct pci_dev *dev); > > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > > struct resource *res, unsigned int reg); > > int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 5ae8608..c1cbb4c 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2631,6 +2631,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. pcie_scan_all Scan all possible PCIe devices. Otherwise we only look for one device below a PCIe downstream port. + driver Provide an override to the devid<->driver mapping + for a specific slot. + Bind PCI slot 0001:02:03.4 to pci-stub by: + driver[0001:02:03.4]=pci-stub pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 73aef51..7a7ed85 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -245,6 +245,7 @@ void pci_bus_add_device(struct pci_dev *dev) * are not assigned yet for some devices. */ pci_fixup_device(pci_fixup_final, dev); + pci_device_setup_driver_override(dev); pci_create_sysfs_dev_files(dev); pci_proc_attach_device(dev); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b7678be..0a3e07c 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4426,6 +4426,65 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) } EXPORT_SYMBOL(pci_fixup_cardbus); +#define DRIVER_OVERRIDE_NAME_LENGTH 64 +#define DRIVER_OVERRIDE_MAP_SIZE 32 + +struct driver_override_entry { + unsigned int domain; + unsigned char bus; + unsigned int devfn; + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; +}; + +static struct driver_override_entry __initdata + driver_override_map[DRIVER_OVERRIDE_MAP_SIZE]; +static int driver_override_num_entries __initdata; + +void pci_device_setup_driver_override(struct pci_dev *dev) +{ + int i; + + for (i = 0; i < driver_override_num_entries; i++) { + if (pci_domain_nr(dev->bus) != driver_override_map[i].domain || + dev->bus->number != driver_override_map[i].bus || + dev->devfn != driver_override_map[i].devfn) + continue; + + dev->driver_override = kstrndup(driver_override_map[i].driver_name, + DRIVER_OVERRIDE_NAME_LENGTH, + GFP_KERNEL); + break; + } +} + +static void __init pci_parse_driver_override(char *str) +{ + unsigned int domain, bus, dev, fn; + char driver_name[DRIVER_OVERRIDE_NAME_LENGTH]; + int ret, next_entry; + char format[] = "[%4x:%2x:%2x.%2x]=%%%ds"; + + sprintf(format + 18, "%%%ds", DRIVER_OVERRIDE_NAME_LENGTH); + ret = sscanf(str, format, &domain, &bus, &dev, &fn, driver_name); + + if (ret != 5) { + pr_err("PCI: Invalid command line: driver%s\n", str); + return; + } + + if (driver_override_num_entries == DRIVER_OVERRIDE_MAP_SIZE) { + pr_err("PCI: Driver map overflow - ignoring driver%s\n", str); + return; + } + + next_entry = driver_override_num_entries++; + driver_override_map[next_entry].domain = domain; + driver_override_map[next_entry].bus = bus && 0xff; + driver_override_map[next_entry].devfn = ((dev & 0x1f) << 3) | (fn & 0x7); + memcpy(driver_override_map[next_entry].driver_name, + driver_name, sizeof(driver_name)); +} + static int __init pci_setup(char *str) { while (str) { @@ -4468,6 +4527,8 @@ static int __init pci_setup(char *str) pcie_bus_config = PCIE_BUS_PEER2PEER; } else if (!strncmp(str, "pcie_scan_all", 13)) { pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); + } else if (!strncmp(str, "driver", 6)) { + pci_parse_driver_override(str + 6); } else { printk(KERN_ERR "PCI: Unknown option `%s'\n", str); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 0601890..023d78b 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -197,6 +197,7 @@ enum pci_bar_type { bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, int crs_timeout); int pci_setup_device(struct pci_dev *dev); +void pci_device_setup_driver_override(struct pci_dev *dev); int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, struct resource *res, unsigned int reg); int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type);
Scanning a lot of devices during boot requires a lot of time. On other scenarios there is a need to bind a driver to a specific slot. Binding devices to pci-stub driver does not work, as it will not differentiate between devices of the same type. Using some start scripts is error prone. The solution leverages driver_override functionality introduced by commit: 782a985d7af26db39e86070d28f987cad21313c0 Author: Alex Williamson <alex.williamson@redhat.com> Date: Tue May 20 08:53:21 2014 -0600 PCI: Introduce new device binding path using pci_dev.driver_override In order to bind PCI slot 0001:02:03.4 to pci-stub use: driver[0001:02:03.4]=pci-stub Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> --- Notes: - For the moment only 32 slots can be assigned specific driver. - I have further ideas on top of this patch based on your reviews. I thought of: - Use wildcards to specify entire buses/devices, something like: driver[0001:02:*.*]=pci-stub - Use comma to separate several devices: driver[0001:02:03.4,0001:02:04.0,...]=pci-stub - Make domain optional: driver[00:03.0]=pci-stub Comments will be appreciated, Thanks, Marcel Documentation/kernel-parameters.txt | 4 +++ drivers/pci/bus.c | 1 + drivers/pci/pci.c | 61 +++++++++++++++++++++++++++++++++++++ drivers/pci/pci.h | 1 + 4 files changed, 67 insertions(+)